Here is Uefa's statement on the issues outside the ground:
"In the lead-up to the game, the turnstiles at the Liverpool end became blocked by thousands fans who had purchased fake tickets which did not work in the turnstiles. This created a build-up of fans trying to get in.
"As a result, the kick off was delayed by 35 minutes to allow as many fans as possible with genuine tickets to gain access.
"As numbers outside the stadium continued to build up after kick off, the police dispersed them with tear gas and forced them away from the stadium.